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Doesn't look like it. Nor do they account for, as someone else pointed out, turning. Even more importantly, at no point during the simulation does a dog run out into the street, a hubcap fall off, or a tire blow out. At the end of their report, the authors mention that humans probably aren't capable of driving within the tolerances required by their system, but they never consider distress/emergency situations.

But, in spite of its limitations, this is an impressive technique and I'm sure that someone will be able to build on it.

I would assume that they would use off-ramp type of turn lane and just adjust the traffic the same way for the cars entering the new direction of travel as they do for the intersections. No one says you have to make only 90deg. turns at the intersection (unless of course you plan on installing this system at existing intersections with no road modification). Howev,er there is still the problem of dogs, stalls, breakdowns and the like.

You're taking this too literally. It's really just a metaphor. Let's say to the north of the intersection is the United States. To the south is Iraq. To the west is our ally Great Britain and to the right is terrorist Michael Moore. Does this make any sense to you? Of course it doesn't.

Now these cars are like diplomats all trying to make peace with eachother. If this doesn't make sense it's because it's complete nonsense.

Next we have the pedestrians and bicycles as mentioned in your post. Let these represent terrorists and weapons of mass destruction. If you're confused then clearly its because this entire situation makes no sense.

To conclude while you may think this simple simulation is designed to control cars, it's really something much larger designed to make the world a more friendly place. And if this doesn't make sense to you, you must buy the product.

In all seriousness though, this has applications far beyond cars, such as increasing the efficiency at factories with conveyor belts and robots, routing data over the internet, more efficient combustion engines, etc. While it would be ideal to evolve the perfect solutions using genetic algorithms, this is a good fix in a less than perfect world.

I have to wonder if these simulations or plans account for bicycles or pedestrians?

They probably account for them by saying this is only for highways, where bicyclists and pedestrians aren't legally allowed (at least in the US) anyway. Besides, you have to start *somewhere*:). In their paper, they list assumptions even greater than !bicycles and !pedestrians:

no TURNS

everybody goes roughly the same speed (not a bad assumption on highway)

No, of course they don't. It's the over simplified "imagine a cow was a perfect sphere" type of engineering.

Even more importantly, motorcycles (or other ptv) given that they travel as fast as cars. Get it wrong on a bike and splat, change the speed of a bike on a bend and splat, you either run wide into oncoming traffic, fall into the verge or stand it up and again run into oncoming traffic.

with the kind of intersection that would justify this kind of investment, it would likely be above or below grade, giving a good chance to offer pedestrians or bikers their own, separated andd safe, passage.

I don't know how well this would mix with a downtown environment, but something like one of the super-busy intersections near an airport or freeway... I think its a good starting point...

That six-lane each way simulation is awesome, but they had better modify the thing before actually rolling it out so that the cars don't go so damn close to each other. Computer control or not, I don't want another guy's car 7" from my bumper at 70 km/h...

they had better modify the thing before actually rolling it out so that the cars don't go so damn close to each other

They may well have done so, just by making the 'length' of the cars longer. You could probably make a similar simulation with a minimum radius around each car, so nobody can be in your 'bubble'; maybe have a maximum number of cars in the intersection at a time. The obvious price is, longer delay. I could live with a 1.5 second 'delay' as opposed to 9.whatever seconds with traffic light

Actually you do, and heres why. If he should slam on his breaks, you will almost instantly hit him. The force you hit him with will be minimal, as he will not have had any time to slow down. Basic physics says if you rear end someone who is doing 68mph, when you are doing 70, will produce a 2mph impact.

Now, you say, wouldn't it be better to have enough room to stop completely, and NOT hit them at all? An excellent idea, but you have to have quite a bit of space to go from 70 to 0 + plus the delta distanc

The force you hit him with will be minimal, as he will not have had any time to slow down. Basic physics says if you rear end someone who is doing 68mph, when you are doing 70, will produce a 2mph impact.

I agree with the second sentence but I'm not sure about the first one. How do you figure that the front car will only have slown down by 2mph by the time the back car hits it?

I wonder if you can apply the same logic to... a kernel thread scheduler

Unlikely, since the simulation assumes that you can predict when the actor reaches the critical section (car to spot in intersection).

Doing that in a thread scheduler requires you to predict how long it will take a thread to execute before it reaches some critical section. That would allow you to solve the halting problem... which we know is unsolvable.

That simulation was pretty impressive when I looked at it. Until I realized something. None of the cars are turning left or right. Theories and math and simulations work great and are often impressive. But real world factors will almost always mess them up.

So one day when there is a way to get from everywhere on earth to every other place on earth without turning left or right give me a call. Until then, let's stop and let people turn left.

The rotary, in it's big-ass Massachusetts form, is one of the most interesting traffic control devices - part fun, part terror, with all of the lane changing and bluffing that Massachusetts is famous for, WITHOUT LINES.

The rotary is a last choice for traffic engineers without the sack to design a 8-way free for all (like Kelly Square in Worcester).

Well, it's initial research isn't it. Clearly there are other factors to consider. But I think it's impressive as 'proof of concept' anyway: indicating that further research (i.e. handling turns, pedestrians, etc) is worthwhile.

As for pedestrians, It's pretty common in busier intersections here in Europe to provide overpasses or underpasses. Hell I've even seen them in Canada and Alaska, and a few places in the states. So where these are worthwhile this issue can even be dropped (and in fact these ki

Have you ever tried to program a traffic simulation? There are few simulations more trivial, so don't be impressed.

Second, traffic simulations based on human behavior are always post hoc analysis. Twiddle the parameters until it looks right, then make up the behavior that fits the parameters. If you've ever had a chance to play with one, they are a lot of fun. Often the whole simulation falls apart with less than a 5 percent change in some parameters.

This could probably be [relatively] easily adapted to allow right turns in the model. Thus you could use it on the busy streets in the center of cities which do not allow left turns. Of course, you still need cars to be computer-controlled for this, so it's kind of a moot point for the forseeable future.

It is called an overpass. As you pointed out this isn't an intersection but a crossing. Just put the roads on different levels and you got no problems.

While intresting it is useless. If the cars are computer controlled you would never need a six lane highway. Why? Humans need lots of space to avoid driving into each other but computers could do it with milimeters to spare (or that is what is claimed) so you would have a 1 lane road with a safety strip for emergencies and such intersection would take the fo

But your "overpass" solution ignores that at some point the cars will need to go into a different overpass level which just another intersection type problem, you'd just be deferring it.

Though maybe deferring the problem makes it easier to solve later; having the cars switch levels when they're in a less congested area of road (without any intersections) might be easier to igure out for example.

RTFA? The overpass/underpass was discussed as the theoretical best-case scenario. The idea behind this is a system that doesn't cost so damn much to build (or create 2-hour delays while they're doing it).

Now all we have to do is convince the general population that their cars are safe in the autonomous control of computers rather than their own two hands.
Sure, *I* know that having automobiles controlled by a sophisticated traffic network would be safer and more efficient -- I read Slashdot, after all -- but I doubt very many people in this country would be so thrilled about the idea of giving up their grip on the steering wheel.

Well, I'm not convinced. My commute is different every day due to construction (OK, now you know I live in Boston) and trucks double-parked and new pot-holes, sanitation trucks doing random things... In short, the route is extremely variable and requires a lot of attention.

I'm not saying that a computer couldn't deal with all this information -- it probably would do very well. However, I suspect that getting the information into the system (where's the crazy woman with the shopping cart right now? Is

Easily solved with controller computers for all stray dogs. The paranoid schizophrenic homeless person with the shopping cart already claims to be controlled by computers, so that's almost like free money when they plan the budget for this thing. As for flat tires and other problems that could make for catastrophe, that pays for itself too, since they've already got a deal inked with Fox for "When Traffic Control Computers Attack!"....

I get about 1000 visitors a month from a sig. Which is quite tolerable. I figure that even a non-frontpage story could give me that many visitors per minute for more than a few hours. That's what I'm worried about.

I wouldn't be willing to relinquish my car to computer control, for several reasons:

1) If only one -- just ONE -- object on the road doesn't play within the bounds of the driving algorithm, mass accidents can happen, because the first car to interact badly with said object now becomes a second unpredictable hazard on the road. With people in control, you only get mass pileups under the harshest of conditions (like blinding rain, snow, or fog).

Wrong. Unless you're not a normal human, your eyes only give you a 24 Hz refresh rate. On top of that, your vision is vastly different between the center of your retinas and the sides (peripheral vision); the peripheral vision can sense motion, but has extr

Large swathes of sideways motion (esp. full screen) on a movie screen at 24fps makes me nauseous. Fast sideways motion on my 7' projection screen at home doing 60Hz interlaced doesn't. Are you sure that our vision works at 24Hz? It seems more like it's 30 samples/second to me, not that you can really measure it quite that way.

Bah, my eyes do much better than 24 Hz. At movie theatres when the camera pans it is very annoying, because 24 Hz isn't fast enough to make the scroll look smooth. It's one of my beefs about going to the movies -- they have made so many advances in sound quality but for the most part image quality is unchanged. I can see the flicker on my monitor unless I crank it up to about 70 Hz.

I can see the flicker on my monitor unless I crank it up to about 70 Hz.

The reason for this is because your lights flicker at 60 Hz (50 Hz outside of USA). For a while, many monitors, for some stupid reason, had a default vertical refresh rate at or near 60 Hz. This produces a beat frequency because of the interaction of the two, causing a visible flicker to humans.

This is false. Your eyes don't see things as "frames," so talking about the "refresh rate" of your eyes is meaningless. 24 frames per second is enough to give the illusion of motion, which is why you can have movies at that speed; however, your eyes can percieve quite a bit more than that. (On the same note, the 60 Hz claim of in the original post was just as nonsensical.)

In the USA at least, commercial airline travel is much much safer than riding in a conventional automobile.

And yet people don't care. They think air travel is dangerous but thinking nothing of their cars that kill 30,000 per year and injure millions per year. In terms of human life, there's a WTC catastrophe *every month* on the highways.

So it's not about safety. It doesn't matter whether an automatic system is safer than a human-controlled system or not. People want contro and don't actually care abo

While this sounds nice and all, it's not terribly realistic. Aside from the legal complications, shooting someone from a moving vehicle is extremely difficult. Shooting someone and actually disabling their vehicle, while still maintaining control of your own, is orders of magnitude more difficult. And lastly, you usually don't know some moron is going to cause an accident until you only have seconds to react, which is barely enough time to try to swerve around them, let along unholster your gun, lower th

Why do cars drive through each other at the intersection?If its just 2 independent lanes, why the cross-layout?And why even bother to simulate 6 lanes if there isnt any lane-changing? (at least i havent seen one)

ok, the cars are SUPPOSED to nearly crash at the intersection. Sorry, ditnt RTFA...

But: If this control system would be THAT perfect, you could easily increase traffic saturation by 300% by removing any safty distance between your cars. If its safe to near miss each other at the intersection, it shoulnt be a problem to drive with only 1 or 2 meters to the guy in front of you...

I know people have already commented on the cars not changing lanes or turning, and the possibility of breakdown, but this system would be easy to exploit maliciously. If an agent didn't slow down the car, or misreported its speed/location, that could make for a lot of... er... amusement?

The problem with roundabouts (and I'm from the UK by the way), is that there has to be a roughly equal traffic flow from each entry point, otherwise the system falls down. If the majority of traffic is following a particular route, say going straight across, and there is very little traffic they have to give way to (as happens during rush hour), then it's almost impossible to join if they have right of way. The only solution is to start putting traffic lights up on them, and that defeats the whole object.

This may not be practical for general traffic, but I could see it being very useful for places where one can control a fleet of individual cooperative vehicles. This could be on a factory floor with robotic delivery vehicles (e.g. in an Amazon-type warehouse), baggage haulers on airport runways, at airports with the airplanes themselves to get to runways, construction sites with heavy machinery, companies with fleets of similar vehicles like at UPS, FedEx, Walmart, military sites with tanks and humvees (using encrypted channels of course), etc.

There are lots of places where you have a need for traffic control with big or many vehicles, in tight spaces. Such resource allocation is a huge part of many problems. That's where they should market this first, I think.

The first thing I thought when I was watching the simulation was it would be nerve-wracking sitting in a car when it looks like it's just gonna plow into another car.
Instead of doing it in an intersection make a bumpercar ride out of it and everynow and again put in some fuzzy numbers and send bumper cars filled with people careening into each other. People would call it fun and they'd pay you to torture them! Muahahahahahahahahaha...

Insurance companies will want real proof that such a system will be stable and as secure as today's intersections before even half-considering it.

Such proof for this system will require that ALL cars in the area be equipped with such systems and an equally large number of intersections handled.

This roadblock to development was what happened to a demo for a system in which cars controlled by computers would follow magnets in a road and drive within 1m of other cars. That was a couple of years back in San Diego.

If cars are going to be automated someday, we'll need to find some compromise which does not require implementation for all vehicles on a road- i.e. a lane for truckers on long stretches of highway.

That's just my 2 cents. Something like this would be really cool should we ever get to this point....or we could just get flying cars and fly over:)

Put the notifiers in the cars and give each the speed that it needs to go to hit the light just as it turns green. Since there are still lights, it still works for old vehicles (without the notifiers). However, it still puts more info in the hands of the traffic light to control when the light is on/off. Note that to really work properly, the cars need to advertise which direction they're going, so it needs GPS functionality with routing as well.

I've given this some thought over the years, for instance when sitting at an intersection when a light is red and no other traffic. I think what is needed is a 2 phase implementation. First mandate that all cars will be equipped with some sort of transponder that traffic control systems can read (robustly). In phase one, new cars would be mandated to have such equipment by say 2008, used cars by 2010. The benefit during the transition period, traffic lights that optimize for transponder cars, and decrease their average wait time. Phase 2 mandate new cars be drivable by a combination of remote and autonomous control by 2015, used cars to be upgraded by 2020. Advantage: several highways allow hands off driving for upgraded cars in transition period. Mandated transponders on older cars alert remote controlled cars to a hazard in the area.

Starting 2020 driving on a highway or in most city-centers without being on autonomous control would be a crime. Starting 2010 driving a vehicle not sending valid transponder signals would be a crime.

Of course the transponder signal will drive privacy advocates nuts, but I don't think you can get to a robust autonomous driving system without it. I suspect transponders are coming anyway for other reasons, so best to make lemonade out of lemons. Yes you will be taxed for in city driving -- sorry, it's coming anyway. Yes cops will know where your car was in any 48-hour period -- get over it. Yes you will no longer be able to speed - who cares as long as I can blog/. while I ride, and my average arrival time is lower due to everyone optimizing the available traffic ways.

As to unexpected hazards like pedestrians, cars will have built in radar (already practical) that reacts much quicker than even the most alert driver. Drivers will have to be insulated legally from any liability for hitting a pedestrian when said pedestrian jaywalks in an autonomous driving zone, as will the autonomous driving system manufactures.

Will children and pets be hit by robot cars? Yes, but congress will have to mandate legal protections as long as aggregate fatalities fall. Gross negligence in equipment manufacture could still be prosecuted, but any system certified by government for use should be immune from legal persecution as long as the accident falls outside of the parameters the government mandates it be able to handle. The legal challenges are the true roadblock, even if aggregate safety is improved.

While we're at it, lets lower the sound level of emergency vehicles, but have a signal override your loud radio to inform you that there is an emergency vehicle approaching. Same for trains. This could lead to some additional pedestrian accidents, but not if pedestrians are trained to use existing traffic systems better. Children could (should?) be equipped with transponders to alert the system to increase safety margins (i.e. slowdown). Of course transponders on children is another hot button topic, but I'm not referring to some 24/7 implant, but a device they carry when in downtown areas, same for the handicapped and the elderly, even your average citizen if they wish to enhance their own safety.

Transponder abuse must be a severely prosecuted crime for obvious reasons, both for sending false signals or for stalking individuals by tracking their signals.

You can fight these changes, which I believe will come, or you can live in a less technologically advanced nation. Other countries come to mind: "autonomous driving mandated... in Japan" (ongoing/. joke). We will not have robot servants, we will not have autonomous highways, we will not have other unthought of applications of technology if we are not willing to allow our physical presence to be tracked in real space (and this means everybody). How that information is used and stored is where we must concentrate or efforts in the privacy fight.

Granted sufficiently intelligent systems would not need transponders and

you can see the system cue the cars on the east -> west road up and create little 'gaps' in the flow across all lanes that sync up with the north/south cars as they cross, nice to look at but it really needs turning and lane crossing, on the low granularity the cars get more clearence which is abit more realistic:P

I haven't even tried to run the simulation yet, but on in an intersection with 3+ lanes, it would seem to me that you'd lane change all non-turning vehicles into the middle lane(s) and do the same cueing for right-hand turns pretty much normally. Maybe only a slightly larger gap, to give the turning car time to catch up with the cars going in his new direction. Left hand turns would need gaps that are slightly out of sync with each other, since they cross the first lane (as if they were simply crossing) but

Localizers and cheap radar can solve your location reference problem; electronic throttle control and fun things like camless engines can solve for precise acceleration. ETC and camless is a next 10 years sort of technology, cheap radar also. Localizers are probably a little further out, but custom versions just for roadways could be made now if the desire was there.

Not anytime soon, but it isn't so far off... *if* there's a will for it.

This simulation is pretty, but with the space they give to cars that narrowly miss each other, I don't want to trust an electronic component in my car to accurately report the length of my vehicle within 1 foot. Imagine the fun as some contractor enters the intersection with an extra 2 feet of board sticking out the back and a perfectly legal red flag on it.

And don't forget you'd have to disable the break pedal because a single hesitation will cause a mul

The cars aren't turning. Are the cars getting highway-style ramps merging parallel into and out of a road, is there an overpass system, or what?

I'm watching the cars (which are represented by orange rectangles); where is their theory being shown? Some of these cars, when moving through the intersection, are just 1-2 pixels away from a perpendicula

It would be nice to know whether that light ahead of you is going to change or not so you can speed up / slow down to compensate. It would probably subdue a ton of Class A personality drivers and make the commute perhaps a bit more enjoyable.In a bunch of cities in Canada, they have a bunch of "If this light is blinking, prepare to stop" lights. Tends to help the traffic flow and mood of the drivers quite a bit.

I have seen congested areas whose intersections have countdown displays next to the walk/don't walk pedestrian lights. I can only surmise they are for drivers because people cross the street against the light all the time anyway.

if the computer system were to suddenly fuck up, a miscaculation or a power outage... there'd be wrecks like insanity, and the drivers' fate would be sealed, as they would have no control over their vehicle to get in a position that wont harm them, or veer out of the way, or whatever.

The problem with all these traffic management systems is that they are attempting to solve the wrong problem. What they should be doing is asking why there are so many people on the road at the same time all going in the same direction.

What about mixing traffic lights with a reservation system? as you get near you signal the computer your intentions early (left/right/straight) and it starts giving you a speed to match, the speed would be tuned to try and prevent you needing to stop or slow down too much which makes everything quicker for everyone, if you did break or you didnt have the system installed (or it malfunctioned) you would just drive like normal and obviously stop if there was a car infront of you or a red light. Technically this already exists - its called 'figuring out how fast you should go' but people either dont bother or get it wrong and end up stopping - the advantage would be that the computer _knows_ exactly when the lights are going to change because its the one doing the changing, there would be no safety issues and the whole thing would be optional? It would be like automated air-traffic-control for cars with the backup feature that cars can stop if needed.

Yes. that's what this article made me think of, and it's something that would give much more immediate benefits than the algorithm itself- a small display in a car that tells the driver whether he should speed up or slow down at any given time based on the traffic around him. It would have to run off a "referee" signal from a central system using an algorithm like this one, so it would reflect overall traffic conditions in the entire area. It could be used to break up traffic jams on highways, or get "in th

That's a highly effective method of driving in some cases... such as ice storms on hilly roads with lots of lights. I recall one year there being a nasty ice storm, and I was taking the main drag home. I was driving 25 in a 45 in some places, but then I got to watch the cars that passed me try to stop before sliding into the intersection at the red light, and then about the time I arrived, it was turning green and I didn't have to slow down.

wider applicability of this? (not meaning to sound like one of those a**holes in today's article about Are-You-Annoying).Forget about vehicles, dogs, pedestrians, etc., and think about a completely different "problem space":how much is this like, and how might it be applied to, architectures for managing traffic flows in nets, LANs, p2p networks, grid computing, email systems, etc.?

You couldn't tell a packet to slowdown so as to arrive at the switch at the right time. Well not until they add the "slowdown" bit, not much change we are still waiting for the evil bit.

In theory you could "synchronize" all the transmitters to a hub/switch so that there are never any collisions. However considering the speed of ethernet combined with the cost of an accurate enough clock I think the collisions are acceptable.

In a way (if I understood it right) a switch is more like a cloverleave style inte

So I've had this idea for a while that could improve traffic a lot with existing technology. The idea is that an OnStar-style navigation system in your car is much more valuable if it reports your average speed in some anonymous way back to a central server, because if enough other people have the same system, it will know the average speed on the road for each of the potential routes it could give you. You are then nicely routed around any areas of congestion, and incidentally all the people without the sy

turning can be solved, the outer most lanes are for turning, and would theirfor not place a lease on the forward motion but would place a lease on the crossing lane so any oncoming traffic the crosses in the turning lane would be told accordingly.

lane changes would have to be allowed only far between intersections, and disallowed in the intersections.

no generic vehicle size could be accounted for, but every vehicle must state it's size when placing lease, so busses could get more intersection time. ALSO, busses should have a higher priority and that could be stated with conditions to acceptance while placing lease.

accidents can be handled via a motion detection system at the intersection seeing non-leased action and routing traffic to other lanes around the incident. if their are 6 lanes, and an accident or breakdown occurs blocking 2 lanes, then the other 4 lanes must be routed for traffic instantly.

Emergency vehicles(EV) must take top priority and must also place a lease as they arrive. other traffic would route around the EV.

pedestrians should not be allowed and high walls and fences should protect such roadways. also, the incedent detection system should be able to see non-lease activity and if it is moving. Then adjust traffic speeds accordingly and signal for human intervention.

=

though these intersections would be autonomous, they would require human monitoring of signaled events, and human can make deccisions and lower traffic speed to adapt.

The same thing that would happen without the system...the other people either 1) Stop, 2) Stop, and help move your vehicle if necessary or 3) Drive right into you because they weren't paying attention.

You would have to train yourself NOT to pay attention just to have the nerve to go through an intersection like that. It really creates for a more dangerous scenario.

It'd also get people used to whizzing by nearly clipping other vehicles, then they'd inevitably do it in unautomated settings, leading to much carnage. Interesting bit of work. BAD idea to even think about implementing it.

Not to mention the expense of equipping every vehicle on the particular road with the control system. Another issue: would

Looks to me like if one car malfunctions, then the whole thing crashes. The degree of spectacularity is dependant upon the speed of the cars and how close the distance is between cars. Brings to mind pictures of 100 car pileups.

No one turns. In addition to safety concerns, dogs, breakdowns, drunk drivers, etc, you hit on something another AC pointed out above (he's at 0, someone mod him up?) that "highways don't have intersections, eh". Really I think this is more applicable to a situation with all-computer control, not really partial or total human control.

Hypothetically, lets say that turning just boils down to scheduling a longer interval in the area where you turn at. So more cars slow down for someone

That patern is due to their spawning code I believe. A car cannot spawn with in 1 second or 1 meter of a car infront of it, and a direction has a fixed fairly high chance of spawning a car every 1/15 of a second (that is the time step), and then it get placed in a legal lane, if no lane is available the car is discarded. The high rate of spawning and the 1 second gap rule will result in the cars being placed into "waves". The diagonals form just is a result from the fact that some car must be infront(2 c

Yeah, you make the best point. Even if the cars are perfectly controlled the machine could break down. So somewhere there's a balance between throughput and failure, with a risk of massive pileup.

I'm trying to think of a way the cars could connect to each other, so that if one fails after the point of no return for entry to the intersection, it would be pulled through by the other car. That way you could mediate the danger of pile up due to failure, by increasing the required distance between the passing